I took my truck to the dealer yesterday and they said I needed new plug wires,I got it back and I does the same thing,which is. It idles rough and at 40 to 42 mph bucks and carries on like the overdrive isn't working. The guy at the dealer told me to put toyota plugs in it and to change the o2 sensor. Does anyone have any other suggestions. Oh I only get 150 miles to a tank of gas.

 

First, I'm guessing that it is a V6 and an auto.

Toyota recommends changing the O2 sensor every 80K miles. You probably have more than 80K. The O2 sensor being bad could contribute to your bad mileage.

If those plugs are bad it would also cause it to run rough. While you are at it you might as well finish the tuneup and do the rotor and cap. It will only cost you an extra $15.

As for the OD not working, I'm not really sure what that could be. I do know that mine shifts into OD at 40mph. Maybe yours is upshifting and downshifting.

I would do the tuneup first and if you are still having problems with the transmission than I would take it to the dealership.

Just my 2 cents

Good Luck

 

What are you rpm's at about 40 mph? If it is in lock up/overdrive The rpms should be like 1700 (line between 1500 and 2000) It is at like 2300 or above you are not in o/d. Always use Toyota parts, Jacob plug wires are P.O.S big mistake on my part.


-Joe

 

You might want to check your AFM. That's what was wrong with mine when my mileage went down.

Steve

 

Hmmm, Im down from about 20-22mpg on the highway to about 16 or so and 14-15 around town, my engine is rough idleing only when Im in gear sitting at the light. (RPM is about 550rpm) My AFM sensor (that's the thingy that bolts to the top of the air box with the little square movable plate right?) is 215,000 miles old.... Im probably going to switch that in a week or 3.... Being a poor college student into sporting clays, modding my yota, and sound systems leaves NO money left over....lol

But does it sound like my amf sensor needs replacement?
Thanks,
Steve

 

First, on Toyota's the KISS method really works. Check your air intake hose which is attached to the throttle body. If there is a slight crack in it, it will pull in air under acceleration and confuse the computer. It will huck and buck and not want to shift. A little duct tape usually fixes it. The new hose is about 63.00 at the dealer.
-Todd
85 4Runner
85 Cressida

 

20-22????:eek:

Mine has NEVER been in this range... And I bought mine 14,000 miles on the ticker.

 

Well, the afm is $700 so...

There is a way to test it but I don' t know how off hand. Try searching or you can take it to the dealer.

Steve

 

14-17mpg is my normal range for mixed driving to more highway driving. In my completely stock form, I believe the best I ever had was about 20mpg. I don't think your 14-16mpg is completely out of the norm....you might also want to look at your idle and adjust it accordingly.

Only after my 90,000 mile service did my truck begin to idle rough. This doesn't happen all the time just maybe 1 out of 15 starts....I know when it's going to happen b/c after the engine turns over it goes directly to a low rpm (500) and then proceeds to fluctuate. If I don't give it a little gas, the truck will sometime stall. I was told at my 90k service that I needed new plug wires, but I opted not to.....

Do you think that having old plug wires w/ the new rotor and cap maybe causing this? If so, maybe I should get those wires replaced. I also remember reading somewhere (does anyone remember this....somebody provided a link to a personal website) that there was a wiring issue w/ the 3rd brake light in the 2nd gen 4R that sometimes caused a rough idle.....

 

I have a similar problem, but the rouge idle goes away after warming up. Dealer said I needed a Injector Rebuild and O2 Sensor. Gonna do the 02 eventually and have been looking at the MotorVac System
www.MotorVac.com

 

Dunno what to say man, I had a set of 225/75r15s on at that time and drove at 65mph from sarasota, fl to gainesville, fl. (A 3.5hr drive at that speed.) Didn't gun the engine the entire drive. I make that drive a lot actually, and lately Im lucky to get 18 where I'd get 20mpg minimum.

btw - the hose between the silencer box and the filter box was loose so I tightened it back up....still no change in gas milage though, and I haven't driven it enough to tell if it has changed the idleing problem yet.

Im REALLY thinking about the KN cold air intake for my 3.0L....

Steve